Keira Knightley is winning plaudits, including a Screen Actors Guild best supporting actress nomination for her role in “The Imitation Game” — but the British star is also celebrating because she is more than three months pregnant, Page Six can exclusively confirm.

Knightley, 29, is expecting her first child with husband James Righton, the co-vocalist and keyboardist for London-based band Klaxons, whom she married last year, multiple sources have confirmed to us.

A glowing Knightley fueled rumors of a pregnancy as she stepped out at the Moët British Independent Spirit Awards on Sunday night — and, despite the sponsor, she appeared to stay away from alcohol. The famously svelte star appeared at her husband’s side in an embroidered and billowy, ivory fur-trimmed Rocha dress very different from her usual fitted style.

Pregnancy rumors first emerged in November when Star magazine reported that she and Righton were expecting and it was a happy surprise for the couple. A source said, “Keira and her stylist have been putting together looks that hide her growing bump.”

On Wednesday, it was announced that her role as codebreaker Joan Clarke opposite Benedict Cumberbatch in wartime drama “The Imitation Game” had earned her a nomination for the prestigious Screen Actors Guild Awards, which are seen as an indicator for upcoming Oscar nods.

At the Jan. 25 SAG Awards, she will go up against Meryl Streep (“Into the Woods”), Naomi Watts (“St. Vincent”), Emma Stone (“Birdman”) and Patricia Arquette (“Boyhood”) for the title of outstanding performance by a female actor in a supporting role.

Keira has previously said that she hopes to have children, but does not plan on giving up her acting career once she becomes a mother.

She told Vogue in 2013: “Would I want to be a stay-at-home mother? No. On the other hand, you should be allowed to do that, as should men, without being sneered at.”

After Page Six broke the story, Knightley’s rep confirmed to ELLE UK on Friday that the actress is expecting a baby, but that she will not be making any further comments.